Method of manufacturing slider of thin-film magnetic head

ABSTRACT

A method of manufacturing a slider includes forming a slider material containing a portion to be the slider body and a head element. The slider material is processed to form an air bearing surface by lapping a surface to be a medium facing surface of the slider material to form a lapped surface that includes a third surface. Selectively etching the lapped surface for form a second surface and after the selectively etching, lapping a part of the lapped surface to form the first surface, the third surface and a border part.

PRIORITY

This is a Divisional of application Ser. No. 11/063,837 filed Feb. 23,2005, now U.S. Pat. No. 7,308,753, which in turn is a Divisional ofapplication Ser. No. 10/011,780 filed Dec. 11, 2001, now U.S. Pat. No.6,882,505. The entire disclosures of the prior applications are herebyincorporated by reference in their entirety.

BACKGROUND

The present invention relates to a slider of a thin-film magnetic headwhich comprises a medium facing surface that faces toward a recordingmedium and a thin-film magnetic head element located near the mediumfacing surface, and to a method of manufacturing such a slider.

Performance improvements in thin-film magnetic heads have been sought asareal recording density of hard disk drives has increased. Suchthin-film magnetic heads include composite thin-film magnetic heads thathave been widely used. A composite head is made of a layered structureincluding a recording head having an induction-type electromagnetictransducer for writing and a reproducing head having a magnetoresistiveelement (that may be hereinafter called an MR element) for reading. MRelements include an anisotropic magnetoresistive (AMR) element thatutilizes the AMR effect and a giant magnetoresistive (GMR) element thatutilizes the GMR effect. A reproducing head using an AMR element iscalled an AMR head or simply an MR head. A reproducing head using a GMRelement is called a GMR head. An AMR head is used as a reproducing headwhere areal recording density is more than 1 gigabit per square inch. AGMR head is used as a reproducing head where areal recording density ismore than 3 gigabits per square inch. It is GMR heads that have beenmost widely used recently.

Performance of the reproducing head is improved by replacing the AMRfilm with a GMR film and the like having an excellent magnetoresistivesensitivity. Alternatively, a pattern width such as the reproducingtrack width and the MR height, in particular, may be optimized. The MRheight is the length (height) between an end of the MR element locatedin the air bearing surface and the other end. The air bearing surface isa surface of the thin-film magnetic head facing toward a magneticrecording medium.

Performance improvements in a recording head are also required as theperformance of a reproducing head is improved. It is required toincrease the recording track density in order to increase the arealrecording density among the performance characteristics of the recordinghead. To achieve this, it is required to implement a recording head of anarrow track structure wherein the width of top and bottom polessandwiching the recording gap layer on a side of the air bearing surfaceis reduced down to microns or a submicron order. Semiconductor processtechniques are utilized to implement such a structure. A pattern width,such as the throat height in particular, is also a factor thatdetermines the recording head performance. The throat height is thelength (height) of pole portions, that is, portions of magnetic polelayers facing each other with a recording gap layer in between, betweenthe air-bearing-surface-side end and the other end. To achieveimprovement in the recording head performance, it is desirable to reducethe throat height. The throat height is controlled by an amount oflapping when the air bearing surface is processed.

As thus described, it is important to fabricate well-balanced recordingand reproducing heads to improve the performance of the thin-filmmagnetic head.

In order to implement a thin-film magnetic head that achieves highrecording density, the requirements for the reproducing head include areduction in reproducing track width, an increase in reproducing output,and a reduction in noise. The requirements for the recording headinclude a reduction in recording track width, an improvement inoverwrite property that is a parameter indicating one of characteristicswhen data is written over existing data, and an improvement in nonlineartransition shift.

In general, a flying-type thin-film magnetic head used in a hard diskdrive and the like is made up of a slider having a thin-film magnetichead element formed at the trailing edge thereof. The slider slightlyflies over a recording medium by means of airflow generated by therotation of the medium.

Reference is now made to FIGS. 32A to 35A, FIGS. 32B to 35B, and FIG. 36to describe an example of a method of manufacturing a related-artthin-film magnetic head element. FIGS. 32A to 35A are cross sectionseach orthogonal to the air bearing surface. FIGS. 32B to 35B are crosssections of the pole portion each parallel to the air bearing surface.

According to the manufacturing method, as shown in FIGS. 32A and 32B, aninsulating layer 102 made of alumina (Al₂O₃), for example, is depositedto a thickness of about 5 to 10 μm on a substrate 101 made of aluminumoxide and titanium carbide (Al₂O₃—TiC), for example. Next, on theinsulating layer 102, a bottom shield layer 103 made of a magneticmaterial is formed for a reproducing head.

On the bottom shield layer 103, a bottom shield gap film 104 made of aninsulating material such as alumina is formed to a thickness of 100 to200 nm, for example, through a technique such as sputtering. On thebottom shield gap film 104, an MR element 105 for reproduction is formedto a thickness of tens of nanometers. Next, a pair of electrode layers106 are formed to be electrically connected to the MR element 105 on thebottom shield gap film 104.

Next, a top shield gap film 107 made of an insulating material such asalumina is formed through sputtering, for example, on the bottom shieldgap film 104, the MR element 105 and the electrode layers 106. The MRelement 105 is embedded in the shield gap films 104 and 107.

Next, on the top shield gap film 107, a top-shield-layer-cum-bottom-polelayer (called a bottom pole layer in the following description) 108having a thickness of about 3 μm is formed. The bottom pole layer 108 ismade of a magnetic material and used for both the reproducing head andthe recording head.

Next, as shown in FIGS. 33A and 33B, a recording gap layer 109 made ofan insulating film such as an alumina film and having a thickness of 0.2μm is formed on the bottom pole layer 108. Next, the recording gap layer109 is partially etched to form a contact hole 109 a for making amagnetic path. Next, a top pole tip 110 for the recording head is formedon the recording gap layer 109 in the pole portion. The top pole tip 110is made of a magnetic material and has a thickness of 0.5 to 1.0 μm. Atthe same time, a magnetic layer 119 made of a magnetic material isformed for making the magnetic path in the contact hole 109 a for makingthe magnetic path.

Next, as shown in FIGS. 34A and 34B, the recording gap layer 109 and thebottom pole layer 108 are etched through ion milling, using the top poletip 110 as a mask. As shown in FIG. 34B, the structure is called a trimstructure wherein the sidewalls of the top pole portion (the top poletip 110), the recording gap layer 109, and a part of the bottom polelayer 108 are formed vertically in a self-aligned manner.

Next, an insulating layer 111 of alumina, for example, having athickness of about 3 μm, is formed over the entire surface. Theinsulating layer 111 is polished to the surfaces of the top pole tip 110and the magnetic layer 119 and flattened.

On the flattened insulating layer 111 a first layer 112 of a thin-filmcoil, made of copper (Cu), for example, is formed for the induction-typerecording head. Next, a photoresist layer 113 is formed into a specificshape on the insulating layer 111 and the first layer 112 of the coil.Heat treatment is performed at a specific temperature to flatten thesurface of the photoresist layer 113. Next, a second layer 114 of thethin-film coil is formed on the photoresist layer 113. Next, aphotoresist layer 115 is formed into a specific shape on the photoresistlayer 113 and the second layer 114 of the coil. Heat treatment isperformed at a specific temperature to flatten the surface of thephotoresist layer 115.

Next, as shown in FIGS. 35A and 35B, a top pole layer 116 for therecording head is formed on the top pole tip 110, the photoresist layers113 and 115 and the magnetic layer 119. The top pole layer 116 is madeof a magnetic material such as Permalloy (NiFe). Next, an overcoat layer117 of alumina, for example, is formed to cover the top pole layer 116.Finally, machine processing of the slider including the forgoing layersis performed to form the air bearing surface 118 of the recording headand the reproducing head. The thin-film magnetic head element is thuscompleted.

FIG. 36 is a top view of the thin-film magnetic head element shown inFIGS. 35A and 35B. The overcoat layer 117 and the other insulatinglayers and films are omitted in FIG. 36.

Reference is now made to FIGS. 37 to 42 to describe the configurationand functions of a related-art slider. FIG. 37 is a bottom view showingan example of the configuration of the air bearing surface of therelated-art slider. FIG. 38 is a perspective view of the related-artslider. In the example shown in FIGS. 37 and 38, the air bearing surfaceof the slider 120 is shaped such that the slider 120 slightly flies overthe surface of a recording medium such as a magnetic disk by means ofairflow generated by the rotation of the recording medium. In thisexample, a thin-film magnetic head element 122 is disposed at a positionnear the air outflow end of the slider 120 (the end on the upper side ofFIG. 37) and near the air bearing surface thereof. The configuration ofthe thin-film magnetic head element 122 is as shown in FIGS. 35A and35B, for example. Portion A of FIG. 37 corresponds to FIG. 35B.

In the example shown in FIGS. 37 and 38, the air bearing surface of theslider 120 has first surfaces 121 a that are closest to the recordingmedium, a second surface 121 b having a first difference in level fromthe first surfaces 121 a, and a third surface 121 c having a seconddifference in level, greater than the first difference in level, fromthe first surfaces 121 a. The first surfaces 121 a are disposed nearboth sides along the width of the slider 120 (the lateral direction inFIG. 37) and around the thin-film magnetic head element 122. The secondsurface 121 b is disposed near the air inflow end (the end on the lowerside of FIG. 37). The remaining part of the air bearing surface, i.e.,the part other than the first and second surfaces 121 a and 121 b,constitutes the third surface 121 c. The first difference in levelbetween the first and second surfaces 121 a and 121 b is about 1 μm. Thesecond difference in level between the first and third surfaces 121 aand 121 c is about 2 to 3 μm.

While the recording medium is rotating, a pressure is created betweenthe recording medium and the first surfaces 121 a of the air bearingsurface of the slider 120 shown in FIGS. 37 and 38, the pressure movingthe slider 120 away from the recording medium. In the air bearingsurface of the slider 120 shown in FIGS. 37 and 38, the second surface121 b is disposed near the air inflow end, and the third surface 121 cis disposed closer to the air outflow end than the second surface 121 bis. Here, while the recording medium is rotating, the air passingthrough between the second surface 121 b and the recording mediumincreases in volume when it reaches the space between the third surface121 c and the recording medium. Accordingly, a negative pressure to drawthe slider 120 toward the recording medium is generated between thethird surface 121 c and the recording medium. As a result, while therecording medium is rotating, the slider 120 flies over the recordingmedium, being inclined such that the air outflow end is closer to therecording medium than the air inflow end is. The inclination of the airbearing surface of the slider 120 with respect to the surface of therecording medium is designed to fall within 1°, for example. The amountof flying of the slider 120 can be reduced by appropriately designingthe shape of the air bearing surface.

The slider 120 is fabricated as follows. First, a wafer that includes aplurality of rows of portions to be sliders (hereinafter called sliderportions), each of the slider portions including the thin-film magnetichead element 122, is cut in one direction to form blocks called barseach of which includes a row of slider portions. The surface of this barto be the air bearing surface is then lapped into a lapped surface.Then, first photoresist masks are formed by photolithography on aportion of this lapped surface, the portion being to be the firstsurfaces 121 a. Using the first photoresist masks, the lapped surface isselectively etched to form a stepped surface that has the firstdifference in level from the lapped surface. The first photoresist masksare then removed. Then, a second photoresist mask is formed byphotolithography on the portion of the lapped surface that is to be thefirst surfaces 121 a and on a portion of the stepped surface, theportion being to be the second surface 121 b. Using this secondphotoresist mask, the stepped surface is selectively etched to form thethird surface 121 c having the second difference in level from thelapped surface. In this way, the first surfaces 121 a, the secondsurface 121 b, and the third surface 121 c are formed. Then, the bar iscut into the individual sliders 120.

FIG. 39 is a cross section illustrating the slider 120 and a recordingmedium 140 in a state in which the recording medium 140 is at rest. InFIG. 39, the slider 120 is shown as sectioned along line 39-39 of FIG.37. FIG. 40 shows the slider 120 as viewed from the upper side of FIG.37.

As shown in FIG. 39, the greater part of the slider 120 is made up ofthe substrate 101 made of aluminum oxide and titanium carbide, forexample. The rest of the slider 120 is made up of an insulating portion127 made of alumina, for example, and the thin-film magnetic headelement 122 and so on formed in the insulating portion 127. The greaterpart of the insulating portion 127 is the overcoat layer 117.

In the slider 120 shown in FIGS. 39 and 40, a protection layer 128, madeof diamond-like carbon (DLC) or the like, is formed on the air bearingsurface so as to protect the bottom shield layer 103, the bottom polelayer 108, the top pole tip 110, the top pole layer 116 and others fromcorrosion.

FIG. 41 is a cross section illustrating the slider 120 and the recordingmedium 140 in a state in which the recording medium 140 has just startedrotation from a resting state. FIG. 42 shows a state in which therecording medium 140 is rotating and the slider 120 is flying over thesurface of the recording medium 140 to perform reading and writing withthe thin-film magnetic head element 122. While the slider 120 is flying,the minimum distance H11 between the slider 120 and the recording medium140 is about 8 to 10 nm, and the distance H12 between the air outflowend of the slider 120 and the recording medium 140 is about 100 to 500nm.

Measures for improving the performance of a hard disk drive, such asareal recording density in particular, include increasing a linearrecording density and increasing a track density. To design ahigh-performance hard disk drive, specific measures to be taken forimplementing the recording head, the reproducing head or the thin-filmmagnetic head as a whole differ depending on whether linear recordingdensity or track density is emphasized. That is, if priority is given totrack density, a reduction in track width is required for both therecording head and the reproducing head, for example.

If priority is given to linear recording density, it is required for thereproducing head, for example, to improve the reproducing output and toreduce a shield gap length, that is, the distance between the bottomshield layer and the top shield layer. Furthermore, it is required toreduce the distance between the recording medium and the thin-filmmagnetic head element (hereinafter called a magnetic space).

A reduction in magnetic space is achieved by reducing the amount offlying of the slider. A reduction in magnetic space contributes not onlyto an improvement in the reproducing output of the reproducing head butalso to an improvement in the overwrite property of the recording head.

The amount of flying of the slider can be reduced, for example, byforming the first, second, and third surfaces having differences inlevel from one another in the air bearing surface of the slider as shownin FIGS. 37 and 38. As described before, however, the formation of theair bearing surface having such a configuration necessitates two stepsof forming a photoresist mask and two steps of etching. Accordingly,forming the first through third surfaces of different levels from oneanother in the air bearing surface of the slider has a problem in thatthe number of steps for manufacturing the slider is large and themanufacturing costs of the slider is therefore high.

On the other hand, as the magnetic space is reduced, the slider islikely to collide with the recording medium, which can result in damageto the recording medium and the thin-film magnetic head element. Toavoid this, it is required to enhance the smoothness of the surface ofthe medium. However, the slider easily sticks to the medium if thesmoothness of the surface of the medium is enhanced. This results in aproblem that the slider is harder to take off from the recording mediumwhen the recording medium starts rotation from a resting state where theslider is in contact with the recording medium.

Conventionally, a crown or a camber is formed on the air bearing surfaceof the slider in order to prevent the slider from sticking to therecording medium. A crown refers to a convex surface which gently curvesalong the length of the slider 120 as shown in FIG. 39. A camber refersto a convex surface which gently curves along the width of the slider120 as shown in FIG. 40. The crown has a difference of elevation C1 onthe order of 10 to 50 nm. The camber has a difference of elevation C2 onthe order of 5 to 20 nm.

Crowns are conventionally formed, for example, by changing theorientation of the bar with respect to the surface plate when lappingthe air bearing surface of the bar.

Cambers are conventionally formed by the following method, for example.That is, after lapping the air bearing surface of the bar to adjust MRheight, slits are made in the bar, using a diamond grinder or the like,at positions at which the slider portions are to be separated. Then, theair bearing surface of the bar is re-lapped lightly on a concave surfaceplate.

In the above-described method for forming cambers, after the MR heightis precisely adjusted by lapping the air bearing surface of the bar, theair bearing surface of the bar is lapped again by about 10 to 20 nm inorder to form the camber. This results in a problem that the MR heightcan deviate from its desired value. Further, according to this method,when the air bearing surface of the bar is lapped on the concave surfaceplate, the bar can be scratched by stain and dust on the surface plate,which results in a problem of a lower yield of the thin-film magneticheads. Further, according to this method, when the air bearing surfaceof the bar is lapped on the concave surface plate, chippings of theelectrode layer connected to the MR element may be jammed and spreadbetween the air bearing surface and the surface plate, producing adefect called a smear. The smear sometimes causes an electric shortcircuit between the MR element and the shield layers. The short circuitcan lower the sensitivity of the reproducing head and produce noise inthe reproducing output, thereby deteriorating the performance of thereproducing head.

Further, if crowns/cambers are to be formed on the air bearing surfacesof the sliders, manufacturing costs of the sliders are raised because ofthe steps of forming the crowns/cambers.

SUMMARY

A first object of the invention is to provide a slider of a thin-filmmagnetic head that is easy to manufacture and can attain reduction inmagnetic space, and a method of manufacturing such a slider.

A second object of the invention is, in addition to the aforementionedfirst object, to provide a slider of a thin-film magnetic head and amethod of manufacturing same, which make it possible to prevent theslider from sticking to the recording medium and to prevent damages to arecording medium or a thin-film magnetic head element due to a collisionbetween the slider and the recording medium.

A slider of a thin-film magnetic head according to the inventioncomprises:

a slider body having: a medium facing surface that faces toward arotating recording medium; an air inflow end; and an air outflow end;and

a thin-film magnetic head element disposed near the air outflow end andnear the medium facing surface of the slider body, wherein:

the medium facing surface has: a first surface including a plurality ofportions that extend in a direction of air passage; and a second surfaceincluding a portion that extends in the direction of air passage, theportion of the second surface being disposed between the plurality ofportions of the first surface, and

the first surface and the second surface have such a difference in levelthat the second surface is located farther from the recording mediumthan the first surface is, the difference in level varying gradually soas to increase with decreasing distance from the air outflow end.

In the slider of a thin-film magnetic head of the invention, thedifference in level between the first and second surfaces variesgradually so as to increase with decreasing distance from the airoutflow end. Therefore, while the recording medium is rotating, the airpassing through between the second surface and the recording mediumgradually increases in volume. As a result, a negative pressure fordrawing the slider toward the recording medium occurs between the secondsurface and the recording medium.

In the slider of a thin-film magnetic head of the invention, the firstsurface and the second surface may form an angle of 10° or smaller.

In the slider of a thin-film magnetic head of the invention, while therecording medium is rotating, the first surface may slant against thesurface of the recording medium such that the smaller the distancebetween a point in the first surface and the air inflow end, the greaterthe distance between the point in the first surface and the recordingmedium. In this case, the first surface and the surface of the recordingmedium may form an angle of 10° or smaller while the recording medium isrotating.

In the slider of a thin-film magnetic head of the invention, the sliderbody may be in contact with the surface of the recording medium whilethe recording medium is at rest, and may stay away from the surface ofthe recording medium while the recording medium is rotating.

In the slider of a thin-film magnetic head of the invention, the mediumfacing surface may further have: a third surface that is located closerto the air outflow end than the first surface is; and a border partlocated between the first surface and the third surface, and the firstsurface may be slanted against the third surface such that the first andthird surfaces altogether make a convex shape bent at the border part.In this case, the first surface and the third surface may form an angleof 10° or smaller.

In the slider of a thin-film magnetic head of the invention, where themedium facing surface has the third surface and the border part, theslider body may be in contact with the surface of the recording mediumwhile the recording medium is at rest, and may stay away from thesurface of the recording medium while the recording medium is rotating.In this case, when the slider body comes into contact with the surfaceof the recording medium, the border part may be the first to makecontact with the surface of the recording medium. When the slider bodytakes off from the surface of the recording medium, the border part maybe the last to depart from the surface of the recording medium.

In the slider of a thin-film magnetic head of the invention, where themedium facing surface has the third surface and the border part,regardless of whether the recording medium is rotating or at rest, theslider body may be in contact with the surface of the recording mediumat the border part, and the first surface may slant against the surfaceof the recording medium such that the smaller the distance between apoint in the first surface and the air inflow end, the greater thedistance between the point in the first surface and the recordingmedium.

In the slider of a thin-film magnetic head of the invention, where themedium facing surface has the third surface and the border part, themedium facing surface may have a recess formed in a region including theborder part.

In the slider of a thin-film magnetic head of the invention, where themedium facing surface has the third surface and the border part, theslider body may include: a substrate portion that has a surface facingtoward the recording medium and makes a base of the thin-film magnetichead element; and an insulating portion that has a surface facing towardthe recording medium and surrounds the thin-film magnetic head element.In this case, the medium facing surface may have a recess formed in aregion including the border part, and the recess may be formed in thesubstrate portion.

In the slider of a thin-film magnetic head of the invention, where theslider body includes the substrate portion and the insulating portion,the slider body may further include a protection layer that covers thesurfaces of the substrate portion and the insulating portion facingtoward the recording medium. In this case, the medium facing surface mayhave a recess formed in a region including the border part, and therecess may be formed in the protection layer. The protection layer maybe made of alumina or diamond-like carbon.

In the slider of a thin-film magnetic head of the invention, where theslider body includes the substrate portion and the insulating portion,the surface of the insulating portion facing toward the recording mediummay be located farther from the recording medium than a part of thesurface of the substrate portion facing toward the recording medium is,the part being adjacent to the surface of the insulating portion facingtoward the recording medium. In this case, the slider body may be incontact with the surface of the recording medium regardless of whetherthe recording medium is rotating or at rest, and a portion of the thirdsurface, the portion belonging to the substrate portion, may be incontact with the surface of the recording medium at least while therecording medium is rotating.

Where the slider body includes the substrate portion and the insulatingportion, the length of the portion of the third surface belonging to thesubstrate portion in the direction of air passage may be equal to orless than 50% the length of the entire substrate portion in thedirection of air passage.

A method of the invention is provided for manufacturing a slider of athin-film magnetic head, the slider comprising: a slider body having amedium facing surface that faces toward a rotating recording medium, anair inflow end, and an air outflow end; and a thin-film magnetic headelement disposed near the air outflow end and near the medium facingsurface of the slider body, wherein: the medium facing surface has: afirst surface including a plurality of portions that extend in adirection of air passage; and a second surface including a portion thatextends in the direction of air passage, the portion of the secondsurface being disposed between the plurality of portions of the firstsurface, the first surface and the second surface having such adifference in level that the second surface is located farther from therecording medium than the first surface is, the difference in levelvarying gradually so as to increase with decreasing distance from theair outflow end.

The method comprises the steps of:

forming a slider material containing a portion to be the slider body andthe thin-film magnetic head element, and

processing the slider material so as to form the medium facing surfaceon the slider material, the medium facing surface having the firstsurface and the second surface.

In the slider of a thin-film magnetic head manufactured by the method ofthe invention, the difference in level between the first and secondsurfaces varies gradually so as to increase with decreasing distancefrom the air outflow end. Therefore, while the recording medium isrotating, the air passing through between the second surface and therecording medium gradually increases in volume. As a result, a negativepressure for drawing the slider toward the recording medium occursbetween the second surface and the recording medium.

In the method of manufacturing the slider of the invention, the slidermaterial may have a surface to be the medium facing surface, and thestep of processing the slider material may include the steps of:selectively etching the surface to be the medium facing surface of theslider material to form the second surface; and, after the formation ofthe second surface, lapping the surface to be the medium facing surfaceof the slider material to form the first surface.

In the method of manufacturing the slider of the invention, the firstsurface and the second surface may form an angle of 10° or smaller.

In the method of manufacturing the slider of the invention, the mediumfacing surface further may have: a third surface that is located closerto the air outflow end than the first surface is; and a border partlocated between the first surface and the third surface, and the firstsurface may be slanted against the third surface such that the first andthird surfaces altogether make a convex shape bent at the border part.In the step of processing the slider material, the slider material maybe processed so as to form the medium facing surface on the slidermaterial, the medium facing surface having the first surface, the secondsurface, the third surface, and the border part.

In the method of manufacturing the slider of the invention, where themedium facing surface has the third surface and the border part, theslider material may have a surface to be the medium facing surface, andthe step of processing the slider material may include the steps of:lapping the surface to be the medium facing surface of the slidermaterial to form a lapped surface including the third surface;selectively etching the lapped surface to form the second surface; and,after the formation of the second surface, lapping a part of the lappedsurface to form the first surface, the third surface, and the borderpart.

In the method of manufacturing the slider of the invention, where themedium facing surface has the third surface and the border part, theslider material may have a surface to be the medium facing surface, andthe step of processing the slider material may include the steps of:selectively etching the surface to be the medium facing surface of theslider material to form the second surface; after the formation of thesecond surface, lapping the surface to be the medium facing surface ofthe slider material to form a lapped surface including the thirdsurface; and lapping a part of the lapped surface to form the firstsurface, the third surface, and the border part.

In the method of manufacturing the slider of the invention, where themedium facing surface has the third surface and the border part, thefirst surface and the third surface may form an angle of 10° or smaller.

In the method of manufacturing the slider of the invention, where themedium facing surface has the third surface and the border part, thestep of processing the slider material may include the step of forming arecess in the medium facing surface at a region including the borderpart.

In the method of manufacturing the slider of the invention, where themedium facing surface has the third surface and the border part, theportion to be the slider body may include: a substrate portion that hasa surface facing toward the recording medium and makes a base of thethin-film magnetic head element; and an insulating portion that has asurface facing toward the recording medium and surrounds the thin-filmmagnetic head element. In this case, the step of processing the slidermaterial may include the step of forming a recess in the medium facingsurface at a region including the border part by etching the substrateportion.

In the method of manufacturing the slider of the invention, where theslider body includes the substrate portion and the insulating portion,the step of processing the slider material may include the step offorming a protection layer for covering the surfaces of the substrateportion and the insulating portion facing toward the recording medium.In this case, the step of processing the slider material may include thestep of forming a recess in the medium facing surface at a regionincluding the border part by etching the protection layer. Theprotection layer may be made of alumina or diamond-like carbon.

In the method of manufacturing the slider of the invention, where theslider body includes the substrate portion and the insulating portion,the surface of the insulating portion facing toward the recording mediummay be located farther from the recording medium than a part of thesurface of the substrate portion facing toward the recording medium is,the part being adjacent to the surface of the insulating portion facingtoward the recording medium. Furthermore, the length of a portion of thethird surface in the direction of air passage, the portion belonging tothe substrate portion, may be equal to or less than 50% the length ofthe entire substrate portion in the direction of air passage.

Other and further objects, features and advantages of the invention willappear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a slider according to a first embodiment of theinvention.

FIG. 2 is a perspective view of the slider according to the firstembodiment of the invention.

FIGS. 3A and 3B are cross sections for illustrating a step in an exampleof a method of manufacturing a thin-film magnetic head element.

FIGS. 4A and 4B are cross sections for illustrating a step that followsFIGS. 3A and 3B.

FIGS. 5A and 5B are cross sections for illustrating a step that followsFIGS. 4A and 4B.

FIGS. 6A and 6B are cross sections for illustrating a step that followsFIGS. 5A and 5B.

FIGS. 7A and 7B are cross sections for illustrating a step that followsFIGS. 6A and 6B.

FIGS. 8A and 8B are cross sections for illustrating a configuration ofan example of the thin-film magnetic head element.

FIG. 9 is a top view of the main part of the thin-film magnetic headelement shown in FIGS. 8A and 8B.

FIG. 10 is a perspective view showing an array of slider portions on awafer to be used in a method of manufacturing the slider according tothe first embodiment of the invention.

FIG. 11 is a perspective view showing a schematic configuration of alapping apparatus for lapping a bar in the first embodiment of theinvention.

FIG. 12 is a block diagram showing an example of a circuit configurationof the lapping apparatus shown in FIG. 11.

FIG. 13 is a side view showing a step in the method of manufacturing theslider according to the first embodiment of the invention.

FIG. 14 is a side view for illustrating a step that follows FIG. 13.

FIG. 15 is a side view for illustrating a step that follows FIG. 14.

FIG. 16 is a side view for illustrating a step that follows FIG. 15.

FIG. 17 is a side view for illustrating a step that follows FIG. 16.

FIG. 18 is a perspective view of a head gimbal assembly incorporatingthe slider according to the first embodiment of the invention.

FIG. 19 is an explanatory view showing the main part of a hard diskdrive in which the slider according to the first embodiment of theinvention is used.

FIG. 20 is a top view of the hard disk drive in which the slideraccording to the first embodiment of the invention is used.

FIG. 21 is a side view showing a state of the slider according to thefirst embodiment of the invention while the recording medium isrotating.

FIG. 22 is a side view showing a state of the slider according to thefirst embodiment of the invention while the recording medium is at rest.

FIG. 23 is a plot for illustrating an example of the waveform ofreproducing output of the thin-film magnetic head element of the slideraccording to the first embodiment of the invention.

FIG. 24 is a side view showing another example of the shape of theslider according to the first embodiment of the invention.

FIG. 25 is a side view showing still another example of the shape of theslider according to the first embodiment of the invention.

FIG. 26 is a side view showing a step in a method of manufacturing aslider according to a second embodiment of the invention.

FIG. 27 is a side view for illustrating a step that follows FIG. 26.

FIG. 28 is a perspective view showing an example of a configuration of aslider according to a third embodiment of the invention.

FIG. 29 is a side view showing a state of the slider shown in FIG. 28while the recording medium is rotating and at rest.

FIG. 30 is a perspective view showing another example of theconfiguration of the slider according to the third embodiment of theinvention.

FIG. 31 is a side view showing a state of a slider according to a fourthembodiment of the invention while the recording medium is rotating andat rest.

FIGS. 32A and 32B are cross sections for illustrating a step of a methodof manufacturing a related-art thin-film magnetic head element.

FIGS. 33A and 33B are cross sections for illustrating a step thatfollows FIGS. 32A and 32B.

FIGS. 34A and 34B are cross sections for illustrating a step thatfollows FIGS. 33A and 33B.

FIGS. 35A and 35B are cross sections of the related-art thin-filmmagnetic head element.

FIG. 36 is a top view of the related-art thin-film magnetic headelement.

FIG. 37 is a bottom view illustrating an example of a configuration ofthe air bearing surface of a related-art slider.

FIG. 38 is a perspective view of the related-art slider.

FIG. 39 is a cross section illustrating the related-art slider and arecording medium in a state in which the recording medium is at rest.

FIG. 40 is a front view of the related-art slider as viewed from theupper side of FIG. 37.

FIG. 41 is a cross section illustrating the related-art slider and therecording medium in a state in which the recording medium has juststarted rotation from a resting state.

FIG. 42 is a cross section illustrating the related-art slider flyingover the surface of the recording medium.

DETAILED DESCRIPTION OF EMBODIMENTS

Preferred embodiments of the invention will now be described in detailwith reference to the accompanying drawings.

Reference is now made to FIGS. 1 and 2 to describe a configuration of aslider of a thin-film magnetic head (hereinafter simply referred to as aslider) according to a first embodiment of the invention. FIG. 1 is aside view of the slider according to the embodiment. FIG. 2 is aperspective view of the slider according to the embodiment.

The slider 20 according to the embodiment comprises a slider body 21 anda thin-film magnetic head element 22. The slider body 21 has: an airbearing surface 30, an air inflow end 41, and an air outflow end 42. Theair bearing surface 30 serves as a medium facing surface that facestoward a rotating recording medium. The air inflow end 41 is an end fromwhich an airflow created by the rotation of the recording medium flowsin. The air outflow end 42 is an end from which this airflow flows out.The thin-film magnetic head element 22 is disposed near the air outflowend 42 and near the air bearing surface 30 of the slider body 21.

The air bearing surface 30 has a first surface 31, a second surface 32,a third surface 33, and a border part 34. The first surface 31 includesa plurality of portions, for example, two portions that extend in adirection of air passage. The second surface 32 includes a portion thatextends in the direction of air passage, the portion being disposedbetween the two portions of the first surface 31. The third surface 33is disposed closer to the air outflow end 42 than the first surface 31is. The border part 34 is located between the first surface 31 and thethird surface 33.

As shown in FIG. 2, the first surface 31 is disposed near the sidewallsof the slider body 21 along the width thereof (in the lateral directionin FIG. 2) and around the thin-film magnetic head element 22.

The second surface 32 lies in parallel to the surface of the slider body21 opposite from the air bearing surface 30. The first surface 31 andthe second surface 32 have such a difference in level that the secondsurface 32 is located farther from the recording medium than the firstsurface 31 is. This difference in level varies gradually so as toincrease with decreasing distance from the air outflow end 42. In otherwords, the first surface 31 makes a plane that slants against thesurface of the slider body 21 opposite from the air bearing surface 30and against the second surface 32. The first surface 31 and the secondsurface 32 preferably form an angle θ1 of 10° or smaller. It is alsopreferable that the angle θ1 formed between the first and secondsurfaces 31 and 32 does not fall below 0.1°.

The third surface 33 lies in parallel to the surface of the slider body21 opposite from the air bearing surface 30. The first surface 31 isslanted against the third surface 33 such that the first and thirdsurfaces 31 and 33 altogether make a convex shape (roof-like shape) bentat the border part 34. The first and third surfaces 31 and 33 preferablyform an angle θ2 of 10° or smaller. It is also preferable that the angleθ2 formed between the first and third surfaces 31 and 33 does not fallbelow 0.1°.

The slider body 21 includes: a substrate portion 23 that has a surfacefacing toward the recording medium (the surface on the lower side ofFIG. 1) and makes a base of the thin-film magnetic head element 22; andan insulating portion 24 that has a surface facing toward the recordingmedium (the surface on the lower side of FIG. 1) and surrounds thethin-film magnetic head element 22. The slider body 21 further includesa protection layer 25 that covers the surfaces of the substrate portion23 and the insulating portion 24 facing toward the recording medium. Thesubstrate portion 23 is made of aluminum oxide and titanium carbide, forexample. The insulating portion 24 is made chiefly of alumina, forexample. The protection layer 25 is made of alumina or diamond-likecarbon, for example.

In the slider 20 of the embodiment, the first through third surfaces 31,32, and 33 of the air bearing surface 30 form concavities/convexitiesfor controlling the orientation of the slider body 21 during therotation of the recording medium. According to the shape of theconcavities/convexities of the air bearing surface 30, a force away fromthe recording medium or a force toward the recording medium can be givento the slider body 21 by means of airflow.

As shown in FIG. 1, the third surface 33 of the air bearing surface 30extends across the substrate portion 23 and the insulating portion 24.The length L1 of a portion of the third surface 33 in the direction ofair passage (the lateral direction in FIG. 1), the portion belonging tothe substrate portion 23, is preferably equal to or less than 50% thelength L0 of the entire substrate portion 23 in the direction of airpassage.

The length L0 of the entire substrate portion 23 in the direction of airpassage is 1.2 mm, for example. Meanwhile, the length L2 of theinsulating portion 24 in the direction of air passage is about 40 to 50μm. Therefore, the length of the slider body 21 in the direction of airpassage is approximately equal to the length L0 of the entire substrateportion 23 in the direction of air passage.

The length (L1+L2) of the third surface 33 in the direction of airpassage is 100 μm to 0.6 mm, for example.

At the air outflow end 42, the slider body 21 has a height (verticallength in FIG. 1) H0 of 0.3 mm, for example. The protection layer 25 hasa thickness of about 3 to 5 nm, for example.

Reference is now made to FIGS. 3A to 8A, FIGS. 3B to 8B, and FIG. 9 todescribe an example of a method of manufacturing the thin-film magnetichead element 22 of the slider according to the embodiment. FIGS. 3A to8A are cross sections each orthogonal to the air bearing surface and thetop surface of the substrate. FIGS. 3B to 8B are cross sections ofmagnetic pole portions each parallel to the air bearing surface.

In this example of the method of manufacturing the thin-film magnetichead element 22, as shown in FIGS. 3A and 3B, an insulating layer 2 madeof alumina (Al₂O₃), for example, is first deposited to a thickness ofabout 5 μm on a substrate 1 made of aluminum oxide and titanium carbide(Al₂O₃—TiC), for example. On the insulating layer 2, a bottom shieldlayer 3, made of a magnetic material such as Permalloy and having athickness of about 3 μm, is formed for the reproducing head. The bottomshield layer 3 is selectively formed on the insulating layer 2 throughplating with a photoresist film as a mask, for example. Then, althoughnot shown, an insulating layer of alumina, for example, is formed overthe entire surface to a thickness of 4 to 5 μm, for example. Theinsulating layer is then polished through chemical mechanical polishing(CMP), for example, so that the bottom shield layer 3 is exposed, andthe surface is flattened.

Next, as shown in FIGS. 4A and 4B, on the bottom shield layer 3, abottom shield gap film 4 serving as an insulating film is formed to athickness of about 20 to 40 nm, for example. Next, an MR element 5 formagnetic signal detection is formed to a thickness of tens of nanometerson the bottom shield gap film 4. One of ends of the MR element 5 isdisposed in the air bearing surface 30. The MR element 5 may be formedthrough selectively etching an MR film formed through sputtering. The MRelement 5 may be an element utilizing a magnetosensitive film thatexhibits magnetoresistivity, such as an AMR element, a GMR element or atunnel magnetoresistive (TMR) element. Next, a pair of electrode layers6 are formed to a thickness of tens of nanometers on the bottom shieldgap film 4. The electrode layers 6 are electrically connected to the MRelement 5. Next, a top shield gap film 7 serving as an insulating filmis formed to a thickness of about 20 to 40 nm, for example, on thebottom shield gap film 4 and the MR element 5. The MR element 5 isembedded in the shield gap films 4 and 7. Examples of insulatingmaterials to be used for the shield gap films 4 and 7 include alumina,aluminum nitride, and diamond-like carbon (DLC). The shield gap films 4and 7 may be formed through sputtering or chemical vapor deposition(CVD).

On the top shield gap film 7, a first layer 8 a of atop-shield-layer-cum-bottom-pale layer (hereinafter called a bottom polelayer) 8 is selectively formed to a thickness of about 1.0 to 1.5 μm.The bottom pole layer 8 is made of a magnetic material and used for bothreproducing head and recording head. The bottom pole layer 8 is made upof the first layer 8 a, and a second layer 8 b and a third layer 8 cdescribed later. The first layer 8 a of the bottom pole layer 8 isdisposed to face at least part of a thin-film coil described later.

Next, the second layer 8 b and the third layer 8 c of the bottom polelayer 8, each having a thickness of about 1.5 to 2.5 μm, are formed onthe first layer 8 a. The second layer 8 b includes a magnetic poleportion of the bottom pole layer 8 and is connected to a surface of thefirst layer 8 a that faces toward a recording gap layer described later(on the upper side of FIGS. 4A and 4B). The third layer 8 c is providedfor connecting the first layer 8 a to a top pole layer described later,and is disposed near the center of the thin-film coil described later. Aportion of the second layer 8 b facing the top pole layer has an endlocated farther from the air bearing surface 30, and the position ofthis end defines the throat height.

The second layer 8 b and the third layer 8 c of the bottom pole layer 8may be made of NiFe (80 weight % Ni and 20 weight % Fe), or NiFe (45weight % Ni and 55 weight % Fe) as a high saturation flux densitymaterial and formed through plating, or may be made of a material suchas FeN or FeZrN as a high saturation flux density material throughsputtering. Alternatively, a material such as CoFe or a Co-baseamorphous material as a high saturation flux density material may beused.

Next, as shown in FIGS. 5A and 5B, an insulating film 9 having athickness of about 0.3 to 0.6 μm is formed over the entire surface.

Next, a photoresist is patterned through a photolithography process toform a frame (not shown) used for making the thin-film coil throughframe plating. Next, the thin-film coil 10 made of copper (Cu), forexample, is formed by frame plating through the use of the frame. Forexample, the thickness of the coil 10 is about 1.0 to 2.0 μm and thepitch is 1.2 to 2.0 μm. The frame is then removed. In the drawingsnumeral 10 a indicates a portion for connecting the coil 10 to aconductive layer (lead) described later.

Next, as shown in FIGS. 6A and 6B, an insulating layer 11 of alumina,for example, having a thickness of about 3 to 4 μm, is formed over theentire surface. The insulating layer 11 is then polished through CMP,for example, until the second layer 8 b and the third layer 8 c of thebottom pole layer 8 are exposed, and the surface is flattened. Althoughthe coil 10 is not exposed in FIG. 6A, the coil 10 may be exposed.

Next, a recording gap layer 12 made of an insulating material is formedto a thickness of 0.2 to 0.3 μm, for example, on the second layer 8 band the third layer 8 c of the bottom pole layer 8 exposed and theinsulating layer 11. In general, the insulating material used for therecording gap layer 12 may be alumina, aluminum nitride, asilicon-dioxide-base material, a silicon-nitride-base material,diamond-like carbon (DLC), and so on. The recording gap layer 12 may befabricated through sputtering or CVD.

Next, a portion of the recording gap layer 12 located on top of thethird layer 8 c of the bottom pole layer 8 is etched to form a contacthole for making the magnetic path. Portions of the recording gap layer12 and the insulating layer 11 that are located on top of the connectingportion 10 a of the coil 10 are also etched to form a contact hole.

Next, as shown in FIGS. 7A and 7B, on the recording gap layer 12, a toppole layer 13 having a thickness of about 2.0 to 3.0 μm is formed toextend from the air bearing surface 30 to the top of the third layer 8 cof the bottom pole layer 8. At the same time, a conductive layer 16having a thickness of about 2.0 to 3.0 μm is formed to be connected tothe portion 10 a of the thin-film coil 10. The top pole layer 13 is incontact with the third layer 8 c of the bottom pole layer 8 andmagnetically coupled thereto through the contact hole formed in theportion on top of the third layer 8 c.

The top pole layer 13 may be made of NiFe (80 weight % Ni and 20 weight% Fe) or a high saturation flux density material such as NiFe (45 weight% Ni and 55 weight % Fe) through plating, or may be made of a materialsuch as FeN or FeZrN as a high saturation flux density material throughsputtering. Alternatively, a material such as CoFe or a Co-baseamorphous material as a high saturation flux density material may beused. To improve the high frequency characteristic, the top pole layer13 may be made up of a number of layers of inorganic insulating filmsand magnetic layers of Permalloy, for example.

Next, the recording gap layer 12 is selectively etched through dryetching, using the top pole layer 13 as a mask. The dry etching may bereactive ion etching (RIE) using a chlorine-base gas such as BCl₂ orCl₂, or a fluorine-base gas such as CF₄ or SF₆, for example. Next, thesecond layer 8 b of the bottom pole layer 8 is selectively etched byabout 0.3 to 0.6 μm through argon ion milling, for example. A trimstructure as shown in FIG. 7B is thus formed. The trim structuresuppresses an increase in the effective track width due to expansion ofa magnetic flux generated during writing in a narrow track.

Next, as shown in FIGS. 8A and 8B, an overcoat layer 17 of alumina, forexample, having a thickness of 20 to 40 μm is formed over the entiresurface. The surface of the overcoat layer 17 is then flattened and pads(not shown) for electrodes are formed on the overcoat layer 17. Finally,lapping of the slider including the foregoing layers is performed toform the air bearing surface 30 of the recording head and thereproducing head. The thin-film magnetic head element is thus completed.

FIG. 9 is a top view illustrating the main part of the thin-filmmagnetic head element shown in FIGS. 8A and 8B. The overcoat layer 17and the other insulating layers and insulating films are omitted in FIG.9.

The thin-film magnetic head element of this example comprises thereproducing head and the recording head (induction-type electromagnetictransducer). The reproducing head includes the MR element 5 for magneticsignal detection, and the bottom shield layer 3 and the top shield layer(bottom pole layer 8) for shielding the MR element 5. Portions of thebottom shield layer 3 and the top shield layer on a side of the mediumfacing surface that faces toward a recording medium, i.e., air bearingsurface 30, are opposed to each other, with the MR element 5 interposedbetween these portions of the bottom shield layer 3 and the top shieldlayer.

The recording head includes the bottom pole layer 8 and the top polelayer 13 magnetically coupled to each other, each of which includes atleast one layer. The bottom pole layer 8 and the top pole layer 13include magnetic pole portions that are opposed to each other andlocated in regions on a side of the air bearing surface 30. Therecording head further includes: the recording gap layer 12 providedbetween the magnetic pole portion of the bottom pole layer 8 and themagnetic pole portion of the top pole layer 13; and the thin-film coil10 at least part of which is disposed between the bottom pole layer 8and the top pole layer 13 and is insulated from the bottom and top polelayers 8 and 13.

The substrate portion 23 of the slider body 21 shown in FIGS. 1 and 2 iscomposed of the substrate 1 of FIGS. 8A and 8B. The insulating portion24 of the slider body 21 is composed mostly of the overcoat layer 17.

Next, the outline of a method of manufacturing the slider according tothe embodiment is described. In the method of manufacturing the slideraccording to the embodiment, first, a wafer that includes a plurality ofrows of portions (hereinafter called slider portions) to be sliders 20is cut in one direction to form blocks called bars each of whichincludes a row of slider portions. Each slider portion includes thethin-film magnetic head element 22 and a portion to be the slider body21. Each bar corresponds to the slider material in the presentinvention.

Next, the air bearing surfaces 30, the air inflow ends 41, and the airoutflow ends 42 are formed on a bar. At this step, the bar is lappedwhile detecting the resistance values of the MR elements 5 in aplurality of slider portions included in the bar so that the sliderportions become identical in MR height and in throat height, therebyforming a lapped surface of the bar, the lapped surface including thethird surface 33. The lapped surface is then etched to form the secondsurface 32. Then, the bar is lapped with its orientation with respect tothe surface plate made different from that in the step of forming thelapped surface mentioned above, thereby forming the first surface 31,the third surface 33, and the border part 34. Finally, the bar is cutbetween adjacent ones of slider portions to separate individual sliders20.

FIG. 10 is a perspective view showing an array of slider portions on awafer. In FIG. 10, the reference numeral 50 represents each sliderportion. Each bar includes a plurality of slider portions 50 aligning ina row in the lateral direction of FIG. 10. For easy understanding, FIG.10 shows the topmost slider portions 50 as having their air bearingsurfaces formed already.

With reference to FIGS. 11 and 12, description will now be given of anexample of the method of lapping the bar while detecting the resistancevalues of the MR elements 5 in the plurality of slider portions 50included in the bar so as to make the slider portions 50 equal in MRheight and in throat height.

FIG. 11 is a perspective view illustrating a schematic configuration ofa lapping apparatus for lapping the bar. This lapping apparatus 51comprises: a table 60; a rotating lapping table 61 provided on the table60; a strut 62 provided on the table 60 by the side of the rotatinglapping table 61; and a material supporter 70 attached to the strut 62through an arm 63. The rotating lapping table 61 has a lapping plate 61a to come to contact with the bar.

The material supporter 70 comprises a jig retainer 73 and three loadapplication rods 75A, 75B and 75C placed in front of the jig retainer 73with specific spacing. A jig 80 is to be fixed to the jig retainer 73.The jig 80 has three load application sections each of which is in theshape of a hole having an oblong cross section. Load application pinsare provided at the lower ends of the load application rods 75A, 75B and75C, respectively. Each of the load application pins has a head to beinserted to each of the load application sections (holes) of the jig 80,the head having an oblong cross section. Each of the load applicationpins is driven by an actuator (not shown) in the vertical, horizontal(along the length of the jig 80) and rotational directions.

The jig 80 has a retainer for retaining a bar. With this jig 80, theretainer and the bar are deformed by applying loads in variousdirections to the three load application sections. The air bearingsurface 30 of the bar is thereby lapped while the throat heights and MRheights of the thin-film magnetic head elements 22 in the bar arecontrolled so that the target values are obtained.

FIG. 12 is a block diagram showing an example of the circuitconfiguration of the lapping apparatus shown in FIG. 11. This lappingapparatus comprises: nine actuators 91 to 99 for applying loads in thethree directions to the load application sections of the jig 80; acontroller 86 for controlling the nine actuators 91 to 99 throughmonitoring the resistance values of a plurality of MR elements 5 in thebar; and a multiplexer 87, connected to the MR elements 5 in the barthrough a connector (not shown), for selectively connecting one of theMR elements 5 to the controller 86.

In this lapping apparatus, the controller 86 monitors the resistancevalues of the MR elements 5 in the bar through the multiplexer 87, andcontrols the actuators 91 to 99 so that throat height and MR height ofevery thin-film magnetic head element 22 fall within a certain limitedtolerance.

Reference is now made to FIGS. 13 to 17 to describe the method ofmanufacturing a slider according to the embodiment in detail. Each ofFIGS. 13 to 17 is a side view of the slider portion 50. The sliderportion 50 includes the substrate portion 23, the insulating portion 24,and the thin-film magnetic head element 22.

In the method of manufacturing a slider according to the embodiment, asshown in FIG. 13, a wafer including a plurality of rows of sliderportions 50 is initially cut in one direction to form bars each of whichincludes a row of slider portions 50. Each bar has a surface 30A to bethe air bearing surfaces 30.

Then, a step shown in FIG. 14 is performed. In this step, the surface30A of the bar is lapped while detecting the resistance values of the MRelements 5 in a plurality of the slider portions 50 included in the barso as to make every slider portion 50 equal in MR height and in throatheight. The lapped surface 33A including the third surface 33 of the airbearing surface 30 is thereby formed for each slider portion 50. At thispoint, the air outflow end 42 is formed for each slider portion 50.

Then, as shown in FIG. 15, the lapped surface 33A is selectively etchedto form the second surface 32. The selective etching of the lappedsurface 33A is effected, for example, by dry etching after forming aphotoresist mask on the lapped surface 33A. The depth of the secondsurface 32 from the lapped surface 33A is about 2 to 3 μm, for example.The etching of the lapped surface 33A is effected, for example, byreactive ion etching (RIE) using a chlorine-base gas such as BCl₂ orCl₂, or a fluorine-base gas such as CF₄ or SF₆, for example.

Then, a step shown in FIG. 16 is performed. In this step, part of thelapped surface 33A is lapped by lapping the bar with its orientationwith respect to the surface plate made different from that in the stepof forming the lapped surface 33A. The first surface 31, the thirdsurface 33, and the border part 34 of the air bearing surface 30 arethereby formed for each slider portion 50. At this point, the air inflowend 41 is formed for each slider portion 50.

Then, as shown in FIG. 17, the protection layer 25 is formed to coverthe surfaces of the substrate portion 23 and the insulating portion 24facing toward the recording medium. The protection layer 25 is made ofalumina or diamond-like carbon, for example. The protection layer 25 hasa thickness of about 3 to 5 nm, for example. Subsequently, the bar iscut between adjacent ones of slider portions 50 into individual sliders20.

Concurrently with the formation of the second surface 32 for each sliderportion 50, edges of the air outflow end 42 may be chamfered.

Reference is now made to FIGS. 18 to 20 to describe a head gimbalassembly and a hard disk drive incorporating the slider 20 of thepresent embodiment. Now, reference is made to FIG. 18 to describe thehead gimbal assembly 220. In a hard disk drive, the slider 20 isdisposed to face toward a hard disk platter 262 that is acircular-plate-shaped recording medium to be rotated and driven. Thehead gimbal assembly 220 comprises the slider 20 and a suspension 221that flexibly supports the slider 20. The suspension 221 incorporates: aplate-spring-shaped load beam 222 made of stainless steel, for example;a flexure 223 to which the slider 20 is joined, the flexure beingprovided at an end of the load beam 222 and giving an appropriate degreeof freedom to the slider 20; and a base plate 224 provided at the otherend of the load beam 222. The base plate 224 is attached to an arm 230of an actuator that moves the slider 20 along the x direction across thetrack of the hard disk platter 262. The actuator incorporates the arm230 and a voice coil motor that drives the arm 230. A gimbal sectionthat maintains the orientation of the slider 20 is provided in theportion of the flexure 223 on which the slider 20 is mounted.

The head gimbal assembly 220 is attached to the arm 230 of the actuator.An assembled body comprising the arm 230 and the head gimbal assembly220 attached to the arm 230 is called a head arm assembly. An assembledbody comprising a plurality of head gimbal assemblies 220 and a carriagewith a plurality of arms is called a head stack assembly, in which thehead gimbal assemblies 220 are each attached to the arms.

FIG. 18 illustrates an example of the head arm assembly. In the head armassembly, the head gimbal assembly 220 is attached to an end of the arm230. A coil 231 that is part of the voice coil motor is fixed to theother end of the arm 230. A bearing 233 is provided in the middle of thearm 230. The bearing 233 is attached to an axis 234 that rotatablysupports the arm 230.

Reference is now made to FIGS. 19 and 20 to describe an example of thehead stack assembly and the hard disk drive. FIG. 19 is an explanatoryview illustrating the main part of the hard disk drive. FIG. 20 is a topview of the hard disk drive. The head stack assembly 250 incorporates acarriage 251 having a plurality of arms 252. A plurality of head gimbalassemblies 220 are each attached to the arms 252 such that theassemblies 220 are arranged in the vertical direction with spacingbetween adjacent ones. A coil 253 that is part of the voice coil motoris mounted on the carriage 251 on a side opposite to the arms 252. Thehead stack assembly 250 is installed in the hard disk drive. The harddisk drive includes a plurality of hard disk platters 262 mounted on aspindle motor 261. Two of the sliders 20 are allocated to each of theplatters 262, such that the two sliders 20 face each other with each ofthe platters 262 in between. The voice coil motor includes permanentmagnets 263 located to face each other, the coil 253 of the head stackassembly 250 being placed between the magnets 263.

The head stack assembly 250 except the slider 20 and the actuatorsupport the slider 20 and align it with respect to the hard disk platter262.

In this hard disk drive, the actuator moves the slider 20 across thetrack of the platter 262 and aligns the slider 20 with respect to theplatter 262. The thin-film magnetic head incorporated in the slider 20writes data on the platter 262 through the use of the recording head andreads data stored on the platter 262 through the use of the reproducinghead.

Reference is now made to FIGS. 21 and 22 to describe the functions andeffects of the slider 20 according to the embodiment. FIG. 21 is a sideview showing a state of the slider 20 while the recording medium 45 isrotating. FIG. 22 is a side view showing a state of the slider 20 whilethe recording medium 45 is at rest.

As shown in FIG. 21, while the recording medium 45 is rotating, theslider body 21 flies by means of the airflow created by the rotation ofthe recording medium 45 and is off the surface of the recording medium45. On the other hand, as shown in FIG. 22, the slider body 21 is incontact with the surface of the recording medium 45 while the recordingmedium 45 is at rest.

As shown in FIG. 21, while the recording medium 45 is rotating, thefirst surface 31 of the air bearing surface 30 slants against thesurface of the recording medium 45 such that the smaller the distancebetween a point in the first surface 31 and the air inflow end 41, thegreater the distance between the point in the first surface 31 and therecording medium 45. While the recording medium 45 is rotating, thethird surface 33 of the air bearing surface 30 is almost parallel to thesurface of the recording medium 45. While the recording medium 45 isrotating, the first surface 31 preferably forms an angle of 10° orsmaller with respect to the surface of the recording medium 45. Whilethe recording medium 45 is rotating, it is also preferable that theangle that the first surface 31 forms with the surface of the recordingmedium 45 is not smaller than 0.1°. The angle that the first surface 31forms with the surface of the recording medium 45 while the recordingmedium 45 is rotating can be controlled according to the shape of theconcavities/convexities of the air bearing surface 30.

According to the embodiment, while the recording medium 45 is rotating,a pressure for moving the slider body 21 away from the recording medium45 occurs between the first surface 31 and the recording medium 45. Inthe embodiment, the difference in level between the first and secondsurfaces 31 and 32 varies gradually so as to increase with decreasingdistance from the air outflow end 42. Therefore, during the rotation ofthe recording medium 45, the air passing through between the secondsurface 32 and the recording medium 45 gradually increases in volume.Consequently, a negative pressure for drawing the slider body 21 towardthe recording medium 45 occurs between the second surface 32 and therecording medium 45. This negative pressure allows a portion of theslider body 21 in the vicinity of the air outflow end 42, in particular,to be close to the recording medium 45 while the medium is rotating.Consequently, according to the slider 20 of the embodiment, a reductionin magnetic space is achieved. In terms of reduction in magnetic space,it is possible for the slider 20 of the embodiment to work equivalentlyor better than a slider whose air bearing surface has three surfaces ofdifferent levels as shown in FIGS. 37 and 38, by appropriately designingthe shape of concavities/convexities of the air bearing surface 30. Thatis, according to the slider 20 of the embodiment, the distance betweenthe thin-film magnetic head element 22 and the surface of the recordingmedium 45 can be made no greater than the distance between the thin-filmmagnetic head element and the surface of the recording medium for thecase of using the slider shown in FIGS. 37 and 38.

The air bearing surface shown in FIGS. 37 and 38 has three surfaces ofdifferent levels. In this case, negative pressure is generated by thesecond surface 121 b and the third surface 121 c whose levels aredifferent from each other. In contrast, according to the embodiment,negative pressure is generated by the second surface 32 having no step.Therefore, air flows more smoothly through between the slider 20 and therecording medium 45 as compared with the case of the slider shown inFIGS. 37 and 38. According to the embodiment, it is thus easy to controlthe orientation of the slider body 21 during the rotation of therecording medium 45.

In the embodiment, when the recording medium 45 shifts from the rotatingstate to the resting state and the slider body 21 comes into contactwith the surface of the recording medium 45, the border part 34 is thefirst to make contact with the surface of the recording medium 45. Whenthe recording medium 45 shifts from the resting state to the rotatingstate and the slider body 21 takes off from the surface of the recordingmedium 45, the border part 34 is the last to depart from the surface ofthe recording medium 45. Thus, the border part 34 functions like a wheelof an aircraft.

As described above, the slider 20 of the embodiment makes contact withthe surface of the recording medium 45 at the border part 34 of theslider body 21. Therefore, as compared with conventional sliders, thearea of the slider body 21 contacting the surface of the recordingmedium 45 is extremely smaller, yielding an extreme reduction in thefrictional resistance between the slider body 21 and the surface of therecording medium 45. Therefore, according to the slider 20 of theembodiment, the initial contact of the slider body 21 with the surfaceof the recording medium 45 and the separation of the slider body 21 fromthe surface of the recording medium 45 can be performed smoothly. As aresult, it is possible to prevent occurrence of damage to the recordingmedium 45 and the thin-film magnetic head element 22 due to a collisionbetween the slider 20 and the recording medium 45.

In the slider 20 of the embodiment, the area of the slider body 21contacting the surface of the recording medium 45 when it is at rest isextremely smaller than in conventional sliders. It is therefore possibleto prevent the slider 20 from sticking to the recording medium 45.

According to the slider 20 of the embodiment, as shown in FIG. 21,during the rotation of the recording medium 45 the first surface 31 ofthe air bearing surface 30 slants against the surface of the recordingmedium 45 such that the smaller the distance between a point in thefirst surface 31 and the air inflow end 41, the greater the distancebetween the point in the first surface 31 and the recording medium 45.As a result, the thin-film magnetic head element 22 gets closer to thesurface of the recording medium 45. Thus, according to the slider 20 ofthe embodiment, during the rotation of the recording medium 45, thethin-film magnetic head element 22 is allowed to be close to the surfaceof the recording medium 45 while the first surface 31 of the air bearingsurface 30 is kept farther from the recording medium 45 than thethin-film magnetic head element 22. Therefore, the embodiment makes itpossible to attain a greater reduction in magnetic space while avoidinga collision between the slider 20 and the recording medium 45.

If the edges of the air outflow end 42 are chamfered, it is possible toprevent a collision between the slider 20 and the recording medium 45with higher reliability.

As has been described, the slider 20 of the embodiment makes it possibleto reduce the magnetic space. Furthermore, it is possible to prevent theslider 20 from sticking to the recording medium 45, and to preventdamage to the recording medium 45 and the thin-film magnetic headelement 22 due to a collision between the slider 20 and the recordingmedium 45.

Through the reduction in the magnetic space, the embodiment makes itpossible to improve the reproducing output and reduce the half width ofthe reproducing output of the reproducing head of the thin-film magnetichead element 22. Consequently, the recording density can be improved.FIG. 23 shows an example of the waveform of the reproducing output ofthe thin-film magnetic head element 22 of the slider 20. In FIG. 23‘PW50’ indicates the half width of the reproducing output. The halfwidth PW50 is the time required for the reproducing output to reach 50percent or greater of the peak value. On the other hand, as a result ofreduction in the magnetic space, it is also possible to improve theoverwrite property and nonlinear transition shift of the recording headof the thin-film magnetic head element 22.

The embodiment thus makes it possible to improve the characteristics ofboth the reproducing head and the recording head of the thin-filmmagnetic head element 22. As a result, it is possible to improve theyield of hard disk drives that implement the slider 20 of theembodiment.

To form the air bearing surface having the three surfaces of differentlevels as shown in FIGS. 37 and 38, two steps of forming a photoresistmask and two steps of etching are required. In contrast, the embodimentinvolves only a single step of forming a photomask and a single step ofetching. Instead, the embodiment requires an extra step of lapping theslider body 21 as compared to the case of forming the air bearingsurface shown in FIGS. 37 and 38. The step of lapping the slider body 21is, however, simpler than the steps of forming a photoresist mask andperforming etching. Thus, according to the embodiment, the process forforming the air bearing surface 30 of the slider 20 is simpler than thatfor forming the air bearing surface shown in FIGS. 37 and 38. Themanufacturing cost of the slider 20 is therefore lower.

In the embodiment, the air bearing surface 30 of the slider 20 is formedeasier than in the cases where crowns or cambers are formed on the airbearing surfaces of sliders. Besides, there will occur no problemassociated with the crown/camber formation. Thus, according to theembodiment it is possible to precisely determine the shape of the airbearing surface 30, improve the yield of the slider 20 and reduce themanufacturing costs of the slider 20, as compared to the cases wherecrowns or cambers are formed on the air bearing surfaces of sliders. Inview of the foregoing, the embodiment of the invention is excellent interms of mass productivity.

In the embodiment, the length L1 of the portion of the third surface 33belonging to the substrate portion 23 in the direction of air passage ispreferably equal to or less than 50% the length L0 of the entiresubstrate portion 23 in the direction of air passage. If this issatisfied, during rotation of the recording medium 45 the length L1 ofthe portion (the portion of the third surface 33 belonging to thesubstrate portion 23) that approaches the surface of the recordingmedium 45 out of the entire substrate portion 23 becomes equal to orless than the length of the portion (the first surface 31) that getsaway from the surface of the recording medium 45. It is thereby possibleto prevent a collision between the slider 20 and the recording medium 45with yet higher reliability.

FIG. 24 is a side view showing another example of the shape of theslider 20 according to the embodiment. In this example, in the airbearing surface 30 the position of the border part 34 between the firstsurface 31 and the third surface 33 coincides with the position of theborder between the substrate portion 23 and the insulating portion 24.In this example, the length of the third surface 33 in the direction ofair passage is about 40 to 100 μm.

FIG. 25 is a side view showing still another example of the shape of theslider 20 according to the embodiment. In this example, in the airbearing surface 30 the border part 34 between the first surface 31 andthe third surface 33 is located between the thin-film magnetic headelement 22 and the air outflow end 42. In this example, the length ofthe third surface 33 in the direction of air passage is about 10 to 50μm.

Reference is now made to FIGS. 26 and 27 to describe a method ofmanufacturing a slider according to a second embodiment of theinvention. The slider 20 of the present embodiment has the sameconfiguration as that of the first embodiment. In the method ofmanufacturing the slider according to the embodiment, as in the firstembodiment, a wafer including a plurality of rows of slider portions 50is initially cut in one direction to form bars each of which includes arow of slider portions 50, as shown in FIG. 13. Each bar has the surface30A to be the air bearing surfaces 30.

Then, in this embodiment the surface 30A of the bar is selectivelyetched to form the second surface 32, as shown in FIG. 26. The etchingis performed in the same manner as that for the case of forming thesecond surface 32 in the first embodiment. The depth of the secondsurface 32 from the surface 30A is about 2 to 3 μm, for example.

Then, a step shown in FIG. 27 is performed. In this step, the bar islapped while detecting the resistance values of the MR elements 5 in aplurality of the slider portions 50 included in the bar so as to makeevery slider portion 50 equal in MR height and in throat height. Thelapped surface 33A including the third surface 33 of the air bearingsurface 30 is thereby formed for each slider portion 50. At this point,the air outflow end 42 is formed for each slider portion 50.

Then, the step shown in FIG. 16 is performed as in the first embodiment.In this step, part of the lapped surface 33A is lapped by lapping thebar with its orientation with respect to the surface plate madedifferent from that in the step of forming the lapped surface 33A. Thefirst surface 31, the third surface 33, and the border part 34 of theair bearing surface 30 are thereby formed for each slider portion 50. Atthis point, the air inflow end 41 is formed for each slider portion 50.

Then, the step shown in FIG. 17 is performed as in the first embodiment.In this step, the protection layer 25 is formed to cover the surfaces ofthe substrate portion 23 and the insulating portion 24 facing toward therecording medium. The protection layer 25 is made of alumina ordiamond-like carbon, for example. The protection layer 25 has athickness of about 3 to 5 nm, for example. Subsequently, the bar is cutbetween adjacent ones of slider portions 50 into individual sliders 20.

The remainder of the configuration, functions and effects of the presentembodiment are the same as those of the first embodiment.

Reference is now made to FIGS. 28 to 30 to describe a slider accordingto a third embodiment of the invention. FIG. 28 is a perspective viewshowing an example of the configuration of the slider according to theembodiment. According to this embodiment, the slider body 21 of theslider 20 makes contact with the surface of the recording medium 45 atthe border part 34 of the air bearing surface 30 regardless of whetherthe recording medium 45 is rotating or at rest.

As shown in FIG. 28, the slider 20 of the embodiment has a plurality ofrecesses 35 formed in the air bearing surface 30 in a region includingthe border part 34. The slider 20 of the embodiment is otherwiseconfigured the same as in the first or second embodiment. According tothe slider 20 of the embodiment, since the air bearing surface 30 hasthe recesses 35 formed in the regions including the border part 34, thearea of the slider body 21 contacting the surface of the recordingmedium 45 becomes smaller than in the first embodiment.

The slider 20 shown in FIG. 28 has the protection layer 25. The recesses35 are formed by etching the protection layer 25.

FIG. 30 shows the slider 20 of the embodiment with no protection layer25. In this slider 20, the recesses 35 are formed by etching thesubstrate portion 23.

In the method of manufacturing the slider 20 of the embodiment, the stepof forming the air bearing surface 30 includes the step of forming therecesses 35 mentioned above. In the method of manufacturing the slider20 having the protection layer 25, the step of forming the recesses 35is performed after the step of forming the protection layer 25. Therecesses 35 are formed by etching the protection layer 25. In the methodof manufacturing the slider 20 having no protection layer 25, the stepof forming the recesses 35 is performed after the step of forming thefirst through third surfaces 31, 32 and 33. The recesses 35 are formedby etching the substrate portion 23. The other steps of the method ofmanufacturing the slider 20 are the same as those in the first or secondembodiment.

Reference is now made to FIG. 29 to describe the functions and effectsof the slider 20 according to the embodiment. FIG. 29 is a side viewshowing a state of the slider 20 while the recording medium 45 isrotating and while it is at rest. As shown in FIG. 29, in thisembodiment the slider body 21 of the slider 20 is in contact with thesurface of the recording medium 45 at the border part 34 of the airbearing surface 30 regardless of whether the recording medium 45 isrotating or at rest. Regardless of whether the recording medium 45 isrotating or at rest, the first surface 31 of the air bearing surface 30slants against the surface of the recording medium 45 such that thesmaller the distance between a point in the first surface 31 and the airinflow end 41, the greater the distance between the point in the firstsurface and the recording medium 45. In either case where the recordingmedium 45 is rotating or at rest, the third surface 33 of the airbearing surface 30 may be in contact with the surface of the recordingmedium 45 or slant against the surface of the recording medium 45 suchthat the smaller the distance between a point in the third surface 33and the air outflow end 42, the greater the distance between the pointin the third surface 33 and the recording medium 45.

The slider 20 of the embodiment allows a greater reduction in magneticspace as compared with the slider 20 of the first or second embodiment.According to the embodiment, since the slider body 21 is always incontact with the surface of the recording medium 45, it is possible toprevent occurrence of a collision between the slider body 21 and therecording medium 45 which would be caused by the slider body 21 cominginto contact with and getting away from the surface of the recordingmedium 45.

According to the slider 20 of the embodiment, since the air bearingsurface 30 has the recesses 35 formed in the regions including theborder part 34, the area of the slider body 21 contacting the surface ofthe recording medium 45 is smaller than in the first or secondembodiment. Frictional resistance between the slider body 21 and thesurface of the recording medium 45 is thereby reduced.

Since the slider 20 of the embodiment allows a greater reduction inmagnetic space as compared with the sliders 20 of the first and secondembodiments, it is possible to achieve a greater improvement in thereproducing output and a greater reduction in half width of thereproducing head. Further, it is also possible to achieve greaterimprovements in the overwrite property and nonlinear transition shift ofthe recording head. Accordingly, a greater improvement in the yield ofhard disk drives can be achieved.

In the slider 20 of the embodiment, the air bearing surface 30 hasconcavities/convexities formed by the first through third surfaces 31,32 and 33 as in the first or second embodiment. In this embodiment, theconcavities/convexities serve to control the orientation of the sliderbody 21 while the recording medium 45 is rotating.

The remainder of the configuration, functions and effects of the presentembodiment are the same as those of the first or second embodiment.

Reference is now made to FIG. 31 to describe a slider according to afourth embodiment of the invention. FIG. 31 is a side view showing astate of the slider 20 while the recording medium 45 is rotating andwhile it is at rest. According to this embodiment, the slider body 21 ofthe slider 20 makes contact with the surface of the recording medium 45regardless of whether the recording medium 45 is rotating or at rest.

In the slider 20 of this embodiment, the third surface 33 of the airbearing surface 30 is formed on a surface of the substrate portion 23that faces toward the recording medium 45. A surface 36 of theinsulating portion 24 facing toward the recording medium 45 is locatedfarther from the recording medium 45 than a part of the surface of thesubstrate portion 23 facing toward the recording medium 45 adjacent tothe surface 36, that is, than the third surface 33. The surface 36constitutes part of the air bearing surface 30. The difference in levelbetween the surface 36 and the third surface 33 is about 3 to 4 nm. Thisdifference in level occurs in the step shown in FIG. 14 or FIG. 27,i.e., the step of forming the surface 33A including the third surface 33for each slider portion 50, because of a difference in hardness betweenthe substrate portion 23 and the insulating portion 24. In the presentembodiment, this difference in level is utilized to reduce the magneticspace.

In the slider 20 of the embodiment, as in the third embodiment, the airbearing surface 30 has a plurality of recesses 35 formed in a regionincluding the border part 34. The slider 20 of the embodiment isotherwise configured the same as in the first or second embodiment.

Now, description will be given of the functions and effects of theslider 20 according to the embodiment. As shown in FIG. 31, the slider20 of the embodiment makes contact with the surface of the recordingmedium 45 at the third surface 33 and the border part 34 of the airbearing surface 30 while the recording medium 45 is rotating. In thisstate, the distance between the surface of the recording medium 45 andthe surface 36 of the insulating portion 24 facing toward the recordingmedium 45 is about 3 to 4 nm. Accordingly, the embodiment can achieve asignificant reduction in magnetic space.

According to the embodiment, the surface 36 of the insulating portion 24facing toward the recording medium 45 makes no contact with the surfaceof recording medium 45. Therefore, the magnetic space can be reducedsignificantly as mentioned above while the thin-film magnetic headelement 22 is kept away from the surface of the recording medium 45. Asa result, it is possible to prevent damage to the thin-film magnetichead element 22 and the recording medium 45 which would be caused bycontact between the thin-film magnetic head element 22 and the recordingmedium 45.

When the recording medium 45 is at rest, the orientation of the slider20 may be the same as that shown in FIG. 31, or that in FIG. 29 wherethe slider body 21 is in contact with the surface of the recordingmedium 45 at the border part 34 of the air bearing surface 30.

The slider 20 of the embodiment achieves a greater reduction in magneticspace as compared with the sliders 20 of the first and secondembodiments. Therefore, as compared with the first and secondembodiments, the present embodiment provides a greater improvement inthe reproducing output and a greater reduction in half width of thereproducing head, as well as greater improvements in the overwriteproperty and nonlinear transition shift of the recording head. As aresult, a greater improvement in the yield of hard disk drives can beachieved.

The remainder of the configuration, functions and effects of the presentembodiment are the same as those of the first or second embodiment.

The present invention is not limited to the foregoing embodiments butmay be practiced in still other ways. For example, the invention may beapplied to a thin-film magnetic head dedicated to reading that has noinduction-type electromagnetic transducer, a thin-film magnetic headdedicated to writing that has an induction-type electromagnetictransducer only, or a thin-film magnetic head that performs reading andwriting with an induction-type electromagnetic transducer.

As has been described, according to the slider of a thin-film magnetichead of the invention, the medium facing surface has the first surfaceincluding a plurality of portions that extend in the direction of airpassage, and the second surface including a portion that extends in thedirection of air passage, the portion of the second surface beingdisposed between the plurality of portions of the first surface. Thefirst surface and the second surface have such a difference in levelthat the second surface is located farther from the recording mediumthan the first surface is. This difference in level varies gradually soas to increase with decreasing distance from the air outflow end. Inthis slider, a negative pressure for drawing the slider toward therecording medium occurs between the second surface and the recordingmedium while the recording medium is rotating. Consequently, accordingto the invention, the slider can be manufactured easily and the magneticspace can be reduced.

In the slider of a thin-film magnetic head of the invention, the mediumfacing surface may further have: a third surface that is located closerto the air outflow end than the first surface is; and a border partlocated between the first surface and the third surface, and the firstsurface may be slanted against the third surface such that the first andthird surfaces altogether make a convex shape bent at the border part.In this case, when the slider body comes into contact with the surfaceof the recording medium, the border part makes the contact with thesurface of the recording medium. Therefore, the invention not onlyattains a reduction in magnetic space but also prevents the slider fromsticking to the recording medium, and prevents damage to the recordingmedium and the thin-film magnetic head element due to a collisionbetween the slider and the recording medium.

In the slider of a thin-film magnetic head of the invention, the sliderbody may be in contact with the surface of the recording medium whilethe recording medium is at rest, and may stay away from the surface ofthe recording medium while the recording medium is rotating. When theslider body comes into contact with the surface of the recording medium,the border part may be the first to make contact with the surface of therecording medium. In this case, the slider body can smoothly startmaking contact with the surface of the recording medium. As a result, itis possible to prevent occurrence of damage to the recording medium andthe thin-film magnetic head element due to a collision between theslider and the recording medium.

In the slider of a thin-film magnetic head of the invention, the sliderbody may be in contact with the surface of the recording medium whilethe recording medium is at rest, and may stay away from the surface ofthe recording medium while the recording medium is rotating. When theslider body takes off from the surface of the recording medium, theborder part may be the last to depart from the surface of the recordingmedium. In this case, the slider body can smoothly separate from thesurface of the recording medium. As a result, it is possible to preventoccurrence of damage to the recording medium and the thin-film magnetichead element due to a collision between the slider and the recordingmedium.

In the slider of a thin-film magnetic head of the invention, regardlessof whether the recording medium is rotating or at rest, the slider bodymay be in contact with the surface of the recording medium at the borderpart, and the first surface may slant against the surface of therecording medium such that the smaller the distance between a point inthe first surface and the air inflow end, the greater the distancebetween the point in the first surface and the recording medium. In thiscase, it is possible to prevent occurrence of a collision between theslider body and the recording medium which would be caused by the sliderbody coming into contact with and getting away from the surface of therecording medium.

In the slider of a thin-film magnetic head of the invention, the mediumfacing surface may have a recess formed in a region including the borderpart. In this case, the area of the slider body contacting the surfaceof the recording medium can be made smaller. As a result, it is possibleto reduce the frictional resistance between the slider body and thesurface of the recording medium.

In the slider of a thin-film magnetic head of the invention, the sliderbody may include: a substrate portion that has a surface facing towardthe recording medium and makes a base of the thin-film magnetic headelement; and an insulating portion that has a surface facing toward therecording medium and surrounds the thin-film magnetic head element.Here, the surface of the insulating portion facing toward the recordingmedium may be located farther from the recording medium than a part ofthe surface of the substrate portion facing toward the recording mediumis, the part being adjacent to the surface of the insulating portionfacing toward the recording medium. In this case, the third surface ofthe medium facing surface can be put into contact with the surface ofthe recording medium to thereby attain a significant reduction inmagnetic space.

In the slider of a thin-film magnetic head of the invention, the lengthof a portion of the third surface in the direction of air passage, theportion belonging to the substrate portion, may be equal to or less than50% the length of the entire substrate portion in the direction of airpassage. In this case, while the recording medium is rotating, thelength of the part that approaches the surface of the recording mediumout of the entire substrate portion becomes less than or equal to thelength of the part that gets away from the surface of the recordingmedium. Therefore, it is possible to prevent collision between theslider and the recording medium with yet higher reliability.

In the slider of a thin-film magnetic head manufactured by the method ofthe invention, the medium facing surface has the first surface includinga plurality of portions that extend in the direction of air passage, andthe second surface including a portion that extends in the direction ofair passage, the portion of the second surface being disposed betweenthe plurality of portions of the first surface. The first surface andthe second surface have such a difference in level that the secondsurface is located farther from the recording medium than the firstsurface is. This difference in level varies gradually so as to increasewith decreasing distance from the air outflow end. In this slider, anegative pressure for drawing the slider toward the recording mediumoccurs between the second surface and the recording medium while therecording medium is rotating. Consequently, according to the invention,the slider can be manufactured easily and the magnetic space can bereduced.

In the method of manufacturing a slider of a thin-film magnetic head ofthe invention, the medium facing surface may further have: a thirdsurface that is located closer to the air outflow end than the firstsurface is; and a border part located between the first surface and thethird surface, and the first surface may be slanted against the thirdsurface such that the first and third surfaces altogether make a convexshape bent at the border part. In the step of processing the slidermaterial, the slider material may be processed so as to form the mediumfacing surface on the slider material, the medium facing surface havingthe first surface, the second surface, the third surface, and the borderpart. In this case, it becomes possible to not only reduce the magneticspace but also prevent the slider from sticking to the recording medium,and prevent damage to the recording medium and the thin-film magnetichead element due to a collision between the slider and the recordingmedium.

In the method of manufacturing the slider of the invention, the step ofprocessing the slider material may include the step of forming a recessin the medium facing surface at a region including the border part. Inthis case, the area of the slider body contacting the surface of therecording medium can be made smaller. As a result, it is possible toreduce the frictional resistance between the slider body and the surfaceof the recording medium.

In the method of manufacturing a slider of a thin-film magnetic head ofthe invention, the slider body may include: a substrate portion that hasa surface facing toward the recording medium and makes a base of thethin-film magnetic head element; and an insulating portion that has asurface facing toward the recording medium and surrounds the thin-filmmagnetic head element. Here, the surface of the insulating portionfacing toward the recording medium may be located farther from therecording medium than a part of the surface of the substrate portionfacing toward the recording medium is, the part being adjacent to thesurface of the insulating portion facing toward the recording medium. Inthis case, the third surface of the medium facing surface can be putinto contact with the surface of the recording medium to thereby attaina significant reduction in magnetic space.

In the method of manufacturing a slider of a thin-film magnetic head ofthe invention, the length of a portion of the third surface in thedirection of air passage, the portion belonging to the substrateportion, may be equal to or less than 50% the length of the entiresubstrate portion in the direction of air passage. In this case, whilethe recording medium is rotating, the length of the part that approachesthe surface of the recording medium out of the entire substrate portionbecomes less than or equal to the length of the part that gets away fromthe surface of the recording medium. Therefore, it is possible toprevent collision between the slider and the recording medium with yethigher reliability.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

1. A method of manufacturing a slider of a thin-film magnetic head, theslider comprising: a slider body having a medium facing surface thatfaces toward a rotating recording medium, an air inflow end, and an airoutflow end; and a thin-film magnetic head element disposed near the airoutflow end and near the medium facing surface of the slider body, themedium facing surface having: a first surface including a plurality ofportions that extend in a direction of air passage; and a second surfaceincluding a portion that extends in the direction of air passage andthat is disposed between the plurality of portions of the first surface,the first surface and the second surface having such a difference inlevel that the second surface is located farther from the recordingmedium than the first surface is, the difference in level varyinggradually so as to increase with decreasing distance from the airoutflow end, the method comprising the steps of: forming a slidermaterial containing a portion to be the slider body and the thin-filmmagnetic head element, and processing the slider material so as to formthe medium facing surface on the slider material, the medium facingsurface having the first surface and the second surface, wherein: themedium facing surface further has: a third surface that is locatedcloser to the air outflow end than the first surface is; and a borderpart located between the first surface and the third surface, the firstsurface being slanted with respect to the third surface such that thefirst and third surfaces altogether make a convex shape bent at theborder part; in the step of processing the slider material, the slidermaterial is processed so as to form the medium facing surface on theslider material, the medium facing surface having the first surface, thesecond surface, the third surface, and the border part; the slidermaterial has a surface to be the medium facing surface, and the step ofprocessing the slider material includes the steps of: lapping thesurface to be the medium facing surface of the slider material to form alapped surface including the third surface; selectively etching thelapped surface to form the second surface; and, after selectivelyetching to form the second surface, lapping a part of the lapped surfaceto form the first surface, the third surface, and the border part.